Modelling growth and nitrogen balance of barley under ambient and future conditions

Selostus: Ohran kasvun ja typpidynamiikan mallintaminen nykyisissä ja tulevaisuuden olosuhteissa

Arbuscular mycorrhizal inoculation increases biomass of Euterpe edulis and Archontophoenix alexandrae after two years under field conditions

Inoculation with arbuscular mycorrhizal fungi (AMF) of tree seedlings in the nursery is a biotechnological strategy to improve growth, survival after transplanting, biomass production and to reduce the use of fertilizers. Archontophoenix alexandrae and Euterpe edulis are palm species used in southern Brazil to produce the palm heart, the latter being included in the list of threatened species due to the overexploitation of its native population. The purpose of this paper was to evaluate the effect of mycorrhizal inoculation on growth and physiological parameters of A. alexandrae and E. edulis. After germination, the seedlings were inoculated (AMF) or not (CTL) with AMF in the treatments. Values of chlorophyll content, biomass and shoot phosphorus were not statistically different between the AMF and CTL treatments, after five months in the greenhouse. Inoculation with AMF significantly increased the levels of starch and soluble carbohydrates in shoots and roots of both species. Under field conditions, AMF had no effect on stem diameter and height after 12 and 24 months, but total plant biomass and leaf, stem and root biomass were greater in AMF than in CTL plants. The data indicated that AMF inoculation in the nursery has a strong effect on biomass accumulation after growing for 24 months under field conditions. Therefore, AMF inoculation should be considered an important strategy to increase growth and production of these economically important tropical palm species.

Conditions de travail, chômage et santé : la situation en Suisse à la lumière de l'Enquête suisse sur la santé 2007

"L'emploi et les conditions de travail ont une grande incidence sur l'équité en santé", note l'Organisation mondiale de la santé (OMS) dans un rapport publié en 2008: ils font partie des principaux déterminants sociaux "à l'origine d'une grande part des inégalités en santé observées entre pays et dans les pays". Ce constat se fonde sur un vaste corpus d'enquêtes et de recherches menées à l'échelle internationale, dont le renouveau ces trois dernières décennies a été stimulé par l'explosion du chômage et de la précarisation de l'emploi, ainsi que par l'intensification du travail. Pour la première fois, une vue chiffrée d'ensemble de cette problématique est également disponible pour la Suisse, basée sur les données de la dernière enquête suisse sur la santé, réalisée en 2007 par l'Office fédéral de la statistique (OFS). L'étude dont nous présentons ici les résultats cherche à répondre à trois questions?: 1) Quelles sont les conditions de travail à risque (physique ou psycho-social) les plus fréquentes? Qui y est le plus exposé, en fonction notamment du sexe, de la position sociale ou de la branche d'activité? 2) Quelles associations peut-on mettre en évidence entre ces conditions de travail et l'état de santé? 3) Quels sont les liens entre le fait d'être au chômage ou de craindre pour son emploi et l'état de santé? Les données analysées révèlent un lien significatif entre les conditions de travail à risques, plus fréquentes que souvent admis, et une santé dégradée chez les personnes concernées. L'association est encore plus forte avec le fait d'être au chômage. Ces réalités sont souvent passées sous silence, en Suisse encore plus qu'ailleurs. Cette étude contribue à les rendre visibles et à instruire ainsi le débat nécessaire sur les conditions économiques et sociales de leur changement. Débat dont l'actualité est redoublée par les conséquences dramatiques sur l'emploi et sur les conditions de travail de l'actuelle crise économique internationale. [Ed.]

Ground-state properties of a dilute homogeneous Bose gas of hard disks in two dimensions

The energy and structure of a dilute hard-disks Bose gas are studied in the framework of a variational many-body approach based on a Jastrow correlated ground-state wave function. The asymptotic behaviors of the radial distribution function and the one-body density matrix are analyzed after solving the Euler equation obtained by a free minimization of the hypernetted chain energy functional. Our results show important deviations from those of the available low density expansions, already at gas parameter values x~0.001 . The condensate fraction in 2D is also computed and found generally lower than the 3D one at the same x.

Dissolution-reprecipitation of zircon at low-temperature, high-pressure conditions (Lanzo Massif, Italy)

An eclogite facies meta-plagiogranite from the Lanzo massif (western Alps, Italy) contains crystals of zircon intimately associated with allanite. Zircon displays different microtextures ranging from pristine, euhedral, and magmatic to fractured, porous varieties with mosaic zoning, and pervasive recrystallization into euhedral microcrystals. Fractures and voids in the recrystallized zircon microcrystals are mainly filled by high-pressure Na-rich pyroxene. Electron backscattered diffraction analysis revealed a similar crystallographic orientation for primary magmatic zircon crystals and microcrystals, with less than 2 degrees misorientation among neighboring microdomains. The textural change is coupled with chemical and isotopic modifications: recrystallized zircon domains contain significantly less Th and light- to mid-REE, but are richer in Sr than magmatic zircon crystals. Magmatic zircon preserves the protolith U-Pb age of 163.5 +/- 1.7 Ma, whereas zircon microcrystals have a mean age of 55 +/- 1 Ma. The coexisting allanite also contains inclusions of Na-rich pyroxene and has chemical features (elevated Sr and Ni contents and lack of Eu anomaly) indicating formation at high pressure. Despite being associated texturally with zircon, allanite yields a younger Th-Pb age of 46.5 +/- 3.0 Ma, suggesting that the Lanzo unit remained at relatively high pressure conditions for similar to 8 m.y. Zircon recrystallization proceeded with volume reduction and loss of material to an alkaline metamorphic fluid that acted as the agent for a coupled dissolution-reprecipitation process. Recrystallization occurred with minimum transport, in a low-strain environment, and was not significantly enhanced by metamictization. The source of the fluid for zircon recrystallization is most probably related to prograde devolatilization reactions in the surrounding serpentinite.

Major environmental change and bonebed genesis prior to the Triassic-Jurassic mass extinction

We present new geochemical and sedimentological data from marginal marine strata of Penarth Bay, south Wales (UK) to elucidate the origin of widespread but enigmatic concentrations of vertebrate hard parts (bonebeds) in marine successions of Rhaetian age (late Triassic). Sedimentological evidence shows that the phosphatic constituents of the bonebeds were subjected to intense phosphatization in shallow current-dominated settings and subsequently reworked and transported basinward by storms. Interbedded organic-rich strata deposited under quiescent and poorly oxygenated conditions record enhanced phosphorus regeneration from sedimentary organic matter into the water column and probably provided the main source of phosphate required for heavy bonebed clast phosphatization. The stratigraphically limited interval showing evidence for oxygen depletion and accelerated P-cycling coincides with a negative 4% organic carbon isotope excursion, which possibly reflects supra-regional changes in carbon cycling and clearly predates the 'initial isotope excursion' characterizing many Triassic-Jurassic boundary strata. our data indicate that Rhaetian bonebeds are the lithological signature of profound, climatically driven changes in carbon cycling and redox conditions and support the idea of a multi-pulsed environmental crisis at the end of the Triassic, possibly linked to successive episodes of igneous activity in the central Atlantic Magmatic Province.

Physical activity under confinement and free-living conditions.

The objective of this study was to investigate the relationship between the physical activity (PA) and its related variables under confinement and in free-living conditions in Asian individuals, where no such information presently exists. The subjects consisted of eighty-six Japanese individuals with a mean age of 38+/-12 years. Under confinement in a large respiratory chamber, the energy expenditure (EE) was measured for 24h. In addition, two moderate walking exercises of 30 min each on a horizontal treadmill were assigned. Free-living measurements of 7 days were also performed using a validated accelerometer. The PA level in the chamber (1.47+/-0.11), expressed as a multiple of the basal EE, was lower than that in free-living conditions (1.53+/-0.12) (p<0.001). However, the two values were closely correlated (r=0.744, p<0.001). Conversely, a residual analysis showed a wide variation in the mean difference for both conditions and revealed a significant systematic error (r=-0.548, p<0.001), thus indicating an increased gap with increasing PA levels in free-living conditions. Similar results were obtained following the exclusion of the imposed exercise sessions. In contrast, the daily step counts under both conditions did not show any correlation. The PA level in the chamber (including and excluding imposed walking exercises) is compatible with the PA level in free-living conditions at the group level, although the daily step counts are unrelated. Thus, the PA level in the chamber may provide valuable information to help us achieve a better understanding of human PA in daily life as it is related to behavioral research.

Influence of the dipolar interactions in the magnetization reversal asymmetry of hard-soft magnetic ribbons

Partial crystallization of the metallic glass Co66Si16B12Fe4Mo2 was performed by annealing at temperatures between 500 and 540°C for 10-20 min, resulting in crystallite volume fractions of (0.7-5)×10¿3 and sizes of 50-100 nm. This two-phase alloy presents a remarkable feature: a hysteresis loop shift that can be tailored by simply premagnetizing the sample in the adequate magnetic field. Shifts as large as five times the coercive field have been obtained which make them interesting for application as magnetic cores in dc pulse transformers. The asymetrical magnetic reversal is explained in terms of the magnetic dipolar field interaction and the observed hysteresis loops have been satisfactorily simulated by a modification of Stoner-Wohlfarth¿s model of coherent rotations.

Optimization of preservation conditions of As (III) bioreporter bacteria.

Long-term preservation of bioreporter bacteria is essential for the functioning of cell-based detection devices, particularly when field application, e.g., in developing countries, is intended. We varied the culture conditions (i.e., the NaCl content of the medium), storage protection media, and preservation methods (vacuum drying vs. encapsulation gels remaining hydrated) in order to achieve optimal preservation of the activity of As (III) bioreporter bacteria during up to 12 weeks of storage at 4 degrees C. The presence of 2% sodium chloride during the cultivation improved the response intensity of some bioreporters upon reconstitution, particularly of those that had been dried and stored in the presence of sucrose or trehalose and 10% gelatin. The most satisfying, stable response to arsenite after 12 weeks storage was obtained with cells that had been dried in the presence of 34% trehalose and 1.5% polyvinylpyrrolidone. Amendments of peptone, meat extract, sodium ascorbate, and sodium glutamate preserved the bioreporter activity only for the first 2 weeks, but not during long-term storage. Only short-term stability was also achieved when bioreporter bacteria were encapsulated in gels remaining hydrated during storage.

Factors affecting snow damage of trees with particular reference to European conditions

Summary

Local size segregation in polydisperse hard sphere fluids

The structure of polydisperse hard sphere fluids, in the presence of a wall, is studied by the Rosenfeld density functional theory. Within this approach, the local excess free energy depends on only four combinations of the full set of density fields. The case of continuous polydispersity thereby becomes tractable. We predict, generically, an oscillatory size segregation close to the wall, and connect this, by a perturbation theory for narrow distributions, with the reversible work for changing the size of one particle in a monodisperse reference fluid.